Two words have pushed fuel-efficient cookstoves in a way that millions of deaths and acres of felled forest could not: climate change.

Early interest in the cookstoves, initially envisioned in the 1970s and '80s as a means of reducing deforestation in developing countries, waned when well-meaning projects failed to deliver results.

Even as the awareness of the health risks that come from poor, inefficient cooking methods grew, cookstove projects largely remained a fringe activity. According to the World Health Organization, more than 1.6 million deaths were attributable to indoor smoke from solid fuels in 2000.

Only now, decades after the first clean cookstove, does it appear that these projects are finally gathering momentum among major institutions. The climate bills in both the U.S. House and Senate set ambitious goals for moving efficient, affordable stoves into 20 million homes throughout the developing world within 5 years.

Energy ministries across several Latin American countries are making an inventory of their cookstove needs to assess their energy consumption. And the U.N. Foundation plans to announce its new Global Alliance for Clean Cookstoves this September.

"Stoves took off when people in developed countries realized it affected our environment," said Mark Bryden, a professor of mechanical engineering at Iowa State University. Socially motivated tinkers and engineers have been working on the problem for decades, but governments and deep-pocketed organizations are relatively new to the fold.

Bryden, who studies combustion -- wood, in particular -- got involved with clean cookstoves in 1998 after learning about the range of the injuries and diseases stemming from unhealthy cooking practices. Smoke inhalation is a cause of or is associated with everything from acute respiratory infections like influenza, pneumonia, tuberculosis and bronchiolitis to deformities among children still in the womb -- such as cleft palates.

Bryden said it was clear to him: "It was shortening women's lives."

Fixing the problem of poor indoor air quality around the world, Bryden said, does not require "impossible levels of money." But, he added, "Because climate change affects us, now we care. I know it's cold, but it's probably true."

Rising awareness about black carbon
Half of the world's population -- roughly 3 billion people -- cook their food and heat their homes by burning coal and biomass material like wood and animal dung, over open fires or rudimentary stoves, according to U.S. EPA. Emissions from these fires are thought to have potent effects on the planet's climate.

Over the last four to five years, black carbon -- a component of soot -- has emerged as a major contributor to global climate change. About 20 percent of black carbon emissions come from biomass burning sourced from activities like cooking.

For many, pushing clean cookstoves represents an opportunity to tackle three major global issues: climate change, public health and deforestation.

"[E]missions of black carbon are the second strongest contribution to current global warming, after carbon dioxide emissions," wrote Veerabhadran Ramanathan, a prominent climate scientist at the Scripps Institution of Oceanography, and Greg Carmichael, a professor of chemical engineering at the University of Iowa, in the April 2008 issue of the journal Nature Geoscience.

As a strong absorber of solar radiation, black carbon is believed to also contribute to the surface warming of the polar and alpine glaciers.

But black carbon stays in the atmosphere for only a few days or weeks, depending on the size of the particles, before the particles are flushed out through rain, snow or other forms of precipitation. This is an extremely short period of time compared to carbon dioxide, which is believed to remain in the atmosphere for decades.

Because of black carbon's short residency in the atmosphere, reducing black carbon emissions is considered a short-term strategy for mitigating global climate change.

Testifying to the House Oversight and Government Reform Committee in 2007, Ramanathan said of cutting black carbon emissions that "at best, it is a short-term measure to probably buy a decade or two, time for implementing CO2 emission reduction strategies."

Not 'rocket science,' but selling them is difficult
Reducing emissions from cookstoves is not a new problem. Engineers and nongovernmental organizations have tried for at least three decades address the problem.

Ashok Gadgil, a senior scientist at Lawrence Berkeley National Laboratory, said previous cookstove initiatives failed for a variety of reasons. "They are all doable," he said, "it's not rocket science."

When the first series of cookstove projects came online in the 1970s and '80s, engineers throughout the developed world designed several excellent stoves in their laboratories and distributed them around the world. But, in Gadgil's opinion, most cookstoves at that time failed to catch on because, while their testing in idealized laboratory settings might have been top-notch, field testing was practically nonexistent.

Stove engineers learned an important lesson: One stove does not fit all.

A stove Gadgil later helped design for the U.S. Agency for International Development resulted in the Berkeley-Darfur Stove. Each one promises to cut wood consumption by half to two-thirds, preventing up to 2 tons of carbon dioxide emissions each year and reducing the number of dangerous wood-collecting trips Sudanese women must make.

The Berkeley-Darfur Stove design was based on a stove used in India. However, before it was deemed suitable for distribution in Darfur, it underwent 14 modifications after several field tests, said Andrée Sosler, executive director of the Darfur Stoves Project. It distributes the stoves in partnership with Oxfam America and the Sustainable Action Group, a Sudanese organization.

Cookstove design depends on what food items are being cooked, what types of wood or other fuel is available and general customer acceptance.

Fighting thousands of years of tradition
Not every stove works in every country or even in different regions of the same country. A stove can be a deeply personal item in many homes, poor or not, and one that does not meet expectations is not useful.

If a cook cannot prepare traditional foods or use traditional pots, then a new stove it is not worth the engineering put into it, experts said. Recently, Sosler and Gadgil agree, this barrier has become widely recognized.

Still, Sosler said, "a lot of people like their own invention."

In an effort to address deforestation, Lawrence Berkeley Lab and the nonprofit World Vision are looking to modify the Berkeley-Darfur stove for Ethiopian use, because of the country's devastated forest resources.

As an important sink for climate-affecting greenhouse gases, forests remain at the mercy of people for whom the life of a tree may stand between them and feeding their families.

Globally, deforestation has slowed over the last 10 years, but "wood fuel accounted for about half of the removed wood," according to the Global Forest Resources Assessment 2010, put out by the U.N. Food and Agriculture Organization earlier this year.

In 2005, wood fuel consumption represented about 73 and 90 percent of wood removals in Asia and Africa, respectively.

Another recent development in the cookstove sector aims to treat the poor more like customers than targets for charity.

Applying a market-based approach to push new stoves
According to Xander Slaski and Mark Thurber, researchers at Stanford University's Program on Energy and Sustainable Development, widespread cookstove adoption among the poor has been slow because three criteria were not met: motivation, affordability and level of engagement.

In their report, "Cookstoves and Obstacles to Technology Adoption by the Poor," published in October 2009, Slaski and Thurber explain that a key selling point of clean-burning stoves to the poor is the demonstration of their "observable benefits."

For example, in urban areas where people tend to purchase their fuel, rather than harvest it, it is often easier to sell the new cookstove on its cost-saving efficiency. "[T]he improvement of health through elimination of indoor air pollution," Slaski and Thurber write, "rarely ranks highly in the calculus of purchasers."

Slaski and Thurber also argue that a more subtle issue is at hand: aesthetics.

"A stove could be seen, for example, as contributing to a cleaner kitchen, adding new cooking functionality, or providing a status symbol associated with modernity," they wrote.

"Poor people like nice things, too," said Don Feil, president and CEO of EnterpriseWorks/VITA, an organization that, among many projects, facilitates the distribution of clean cookstoves in Ghana. With the exception of communities in extreme distress, like Darfur or Haiti after the January earthquake, Feil said, generally, "if you don't pay for it, you don't value it."

Gadgil agreed, saying the goal is not to treat the stove solely as "charity."

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